West Pacific/2015/10W/Archive/15
Public advisory TROPICAL STORM LINFA PUBLIC ADVISORY NUMBER 15 WIKI-HURRICANES FORECASTING CENTER 6:00 AM JST MON JUL 06 2015 ...LINFA LESS ORGANIZED... SUMMARY OF 6:00 AM JST...21:00 UTC...INFORMATION ------------------------------------------------------------------- LOCATION...18.3N 119.3E CENTER POSITION CONFIDENCE: MEDIUM ABOUT 280 MI...450 KM NNW OF MANILA, PHILIPPINES MAXIMUM SUSTAINED WINDS...45 KT...50 MPH...85 KM/H MINIMUM BAROMETRIC PRESSURE...992 MB...29.30 INCHES PRESENT MOVEMENT...STATIONARY DISCUSSION AND 48-HOUR OUTLOOK --------------------------------------------- At 6:00 am JST, the center of Tropical Storm Linfa was situated near 18.3N 119.3E, about 280 miles (450 km) north-northwest of Manila, Philippines. Maximum sustained winds were 45 knots (50 mph, 85 km/h), with higher gusts. The minimum barometric pressure was 992 millibars (hPa; 29.30 inHg), and the cyclone was stationary. Linfa is expected to recurve northward, where conditions may be more favorable for intensification until the cyclone moves ashore Taiwan in a few days. NEXT ADVISORY ------------------- Next complete advisory at 12:00 pm JST. $$ Forecaster TAWX14 Discussion TROPICAL STORM LINFA PUBLIC DISCUSSION NUMBER 15 WIKI-HURRICANES FORECASTING CENTER 6:00 AM JST MON JUL 06 2015 Linfa has degraded a bit in organization compared to the previous advisory package. Although spiral banding continues to be prominent, the extent and presentation of deep convection in association with the cyclone has decreased since earlier, with the low-level circulation now exposed on the northern side of the convective mass. Recent satellite intensity estimates were T2.0/30kt from JTWC, T2.5/35kt from SAB, and T3.1/47kt from UW-CIMSS ADT. A blend of these data would yield 35kt, making Linfa a low-end tropical storm, but seeing as though surface winds have continually been observed stronger than the satellite presentation would lead one to believe, the initial intensity has been lowered to a potentially generous 45kt. Satellite animations indicate that Linfa has slowed since the previous advisory, and the cyclone is–at least for right now–stationary. However, over the coming hours, it should begin a slow northward motion as it feels a weakness between the subtropical ridge across the West Pacific and an upper-level trough across northeastern China. Although the trajectory of Linfa may change erratically with the cyclone situated within a col region, the general northward motion is expected to continue through 48 hours. This should bring the tropical storm ashore in Taiwan. After day 2, the shallowness of Linfa, the potential for interaction with Chan-hom, and the continued presence of the upper-level trough/low across northeastern China should all direct it on a north-northwestward track into the mainland. There is good agreement between the GFS and ECMWF for this solution, but the forecast remains one of low confidence due to the potential for a tropical-cyclone-to-tropical-cyclone interaction. Maps from UW-CIMSS indicate that Linfa is undergoing a high 20 to 30 knots of wind shear. This shear is forecast to continue for another 36 to 48 hours, and the potential for Linfa to intensify substantially does not appear as high as before; in fact, it would not be at all surprising if the cyclone actually weakened additionally. However, the GFS indicates the potential for anticyclonic flow to become established a short time before Linfa moves into Taiwan in approximately 48 hours, so slight intensification is possible then. The updated forecast is lower than the previous one and now indicates dissipation by the end of the forecast period as the cyclone tracks into mainland China. INIT 05/2100Z 18.3N 119.3E 45 KT 50 MPH 12H 06/0600Z 19.0N 119.3E 40 KT 45 MPH 24H 06/1800Z 20.3N 119.4E 35 KT 40 MPH 36H 07/0600Z 21.2N 119.9E 40 KT 45 MPH 48H 07/1800Z 22.3N 120.8E 50 KT 60 MPH...APPROACHING TAIWAN 72H 08/1800Z 25.6N 119.7E 30 KT 35 MPH...INLAND MAINLAND CHINA 96H 09/1800Z...DISSIPATED $$ Forecaster TAWX14